OriCAR-017 Chimeric Antigen Receptor (CAR) Modified T Cells for the Treatment of R/RMM

Main Inclusion Criteria: * Diagnosis of R/RMM according to the IMWG criteria; * Expected survival period is \>12 weeks; * Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1 or 2 at the time of ICF signature; * The expression of GPRC5D in bone marrow plasma cells membrane is more than 20% by flow cytometry and/or immunohistochemistry, multiple myeloma with measurable lesions, and at least one of the following criteria must be met: 1. Serum M protein \>5 g/L; 2. Urine M protein level \>200 mg/24 hour; 3. Serum free light chain (sFLC) \>100 mg/L and K/λ FLC ratio is abnormal; 4. Primitive immature or monoclonal plasma cells \>5% by bone marrow cytology or flow cytometry. * Subjects who had received at least 3 prior lines of therapy including (but not limited to) immunomodulatory drugs (IMiDs), proteasome inhibitors, anti-CD38 monoclonal antibodies, etc., but have failed treatment, including those who have experienced relapse (within 12 months), refractory or intolerant to the last line treatment regimen. Main Exclusion Criteria: * Smoldering myeloma (asymptomatic) * Multiple myeloma with only extramedullary lesions; * Plasma cell leukemia; * Concurrent amyloidosis; * Central nervous system metastasis, leptomeningeal disease or metastatic central compression; * HBsAg or HbcAb is positive, and the quantitative detection of hepatitis B virus (HBV) DNA in peripheral blood is more than 100 copies/L; hepatitis C virus (HCV) antibody and HCV RNA in peripheral blood is positive; human immunodeficiency virus (HIV) antibody positive; syphilis antibody is positive at Screening; Cytomegalovirus DNA test is positive; * Had hypersensitivity or intolerance to any drug/excipient (including conditioning chemotherapy) used in this study; * Previously received treatment targeting GPRC5D, including but not limited to antibodies, ADC, or CAR-T; * Subjects who received autologous hematopoietic stem cell transplantation (ASCT) within 8 weeks of Screening Visit or who plan to undergo ASCT during the study; * Any uncontrolled active infection within 4 weeks prior to ICF signing or leukapheresis requires parenteral antibiotic, antiviral, or antifungal treatment * Major surgery within 28 days prior to Screening Visit with the exception of a biopsy and an insertion of a central venous catheter or during the study; * Subjects who received allogeneic stem cell therapy; * Subjects complications or other conditions evaluated by investigators may affect compliance with the protocol or make them unsuitable to participate in this study; * Pregnant or breastfeeding.